1. Field of the Invention
The present invention relates to a solid electrolytic capacitor, and to a method of manufacturing the solid electrolytic capacitor.
2. Description of the Related Art
In electronic circuits, capacitors have conventionally been popularly employed. In particular, solid electrolytic capacitors are widely employed in electronic circuits, because of their relatively small size and large capacitance.
Conventional solid electrolytic capacitors include a porous sintered body with an anode wire sticking out therefrom. On a surface of the porous sintered body, a dielectric layer and a solid electrolyte layer are stacked. A washer is fitted to a base portion of the anode wire. The washer is made of an insulative material such as a fluorine resin. The washer includes a hole for the anode wire to pass therethrough. Description of such a solid electrolytic capacitor can be found, for example, in Japanese Patent Application Laid-open No. 2007-305930.
In a manufacturing process of the solid electrolytic capacitor, the porous sintered body is soaked, for example, in aqueous solution of manganese nitrate, to form the solid electrolyte layer. In such an instance, if the anode wire is put into the manganese nitrate aqueous solution without a washer fitted thereto, the manganese nitrate aqueous solution will spread up along the anode wire. Such upward spreading leads to emergence of a leak current in the solid electrolytic capacitor made up as a finished product. Conventionally, to prevent the upward spreading, a washer is fitted around the anode wire before the porous sintered body is soaked in the manganese nitrate aqueous solution.
In the conventional solid electrolytic capacitor, however, there may be a small gap formed between the washer and the anode wire. Such a gap may induce the manganese nitrate aqueous solution to spread up owing to capillary action.